RapidIO: The Next Generation Communication Fabric For Embedded Application

8.12. SYSTEM MAINTENANCE

Perhaps of equal importance to the operation of the data link itself are the methods for initializing, configuring, and maintaining the system during operation. For products to be interoperable, the system maintenance should be completely specified. This section describes the system maintenance operations that parallel RapidIO end points are required to support.

8.12.1. Port Initialization

Before a parallel port can exchange packets with another port, the ports and the link connecting the two ports must be initialized. In addition, each 16-bit wide port must decide whether to operate in 8-bit or 16-bit unless it has been statically configured for 8-bit or 16-mode.

8.12.1.1. Port Width Mode Selection

All 16-bit parallel RapidIO ports should be capable of operating in both 8-bit and 16-bit modes. The width mode in which a 16-bit port operates may be either statically or dynamically con-figured. If the width mode of a port is statically configured, the port will operate correctly only if connected to a port operating in the same width mode. If the width mode of a 16-bit port is not statically configured, the width mode is determined as part of the port initialization process.

When operating in 8-bit mode, only the signal pairs and are used. The 16-bit mode ...